1. Field of the Invention
The invention in general relates to appliances that operate by changing microwave energy to heat energy and conducting the heat to food by contact, and more particularly to such appliances that can be used to grill foods.
2. Statement of the Problem
Appliances that heat grillable food or other grillable substances by causing microwave energy to be absorbed by an intermediate body, such as a block of ferrite, which in turn transfers heat to the grillable food, which we shall refer to herein as microwave grills, have been known for more than twenty years. These appliances inherently require no ventilation of burned fuels and thus can be used in a small kitchen, use a ready source of energy, and are very fast as compared to conventional grills. Yet a commercially successful microwave grill has never been produced. The reason is that prior art microwave grills have never reached the degree of reliability and ease of use expected for kitchen appliances, particularly in the upscale homes and businesses that would tend to use such grills.
U.S. Pat. No. 4,362,917 issued Dec. 7, 1982 to Freedman and Bowen describe a block of ferrite binded to a microwave transparent cover. U.S. Pat. No. 4,454,403 issued Jun. 12, 1984 to Teich and Dudley describes a silicone material having ferrite material dispersed within the silicone binded to a microwave transparent cover. The ferrite material in these references continuously contacts the microwave transparent cover and transfers heat across the whole of the microwave transparent cover making the microwave transparent cover uncomfortable to the touch of a user. In addition, these designs do not include a suitable means for handling grease and other liquids that are generated in the grilling process. U.S. Pat. No. 5,736,718 issued Apr. 7, 1998 to Levinson describes a vertical microwave grilling apparatus with a separate collection container. This arrangement requires alignment between the grilling apparatus and the collection container and is really too messy to appeal to the average upscale griller. All known prior art microwave grill designs that had separate grills and grill housings also allowed grease, water and other liquids to get into the areas between the grills and housings. At the same time, the prior art designs did not consider the fact that the appliances were likely to be washed in a dishwasher, and allowed water to seep between the outside cover and base and the grill elements. Prior art grills are generally not capable of being submerged in water, which expedites the cleaning process. Further, prior art designs had unwieldy hinges that did not account for differing user preferences and needs and further contributed to messiness by not permitting easy separation of the cover and base. Thus, it is evident that if the advantageous properties inherent in microwave grills are to be enjoyed by the public, a significant advance in such grills is required.
The present invention advances the art and helps to overcome the aforementioned problems by providing a microwave grilling appliance that includes all the inherent advantages of a microwave griller and at the same time is easy to use and does not result in undesirable messiness.
The microwave grill according to the invention provides a base grill element and base that are thermally isolated. The microwave griller according to the invention provides a liquid-tight seal between the grill element and base. Similarly, the microwave grill according to the invention includes a cover grill element and cover that are thermally isolated. The microwave grill according to the invention also includes a liquid-tight seal between the cover grill element and the cover. The microwave grill according to the invention includes a trough about the base grill element that effectively prevents grease and liquids generated in the grill process from overflowing the grill unit. The microwave grill according to the invention provides a hinge assembly that permits the cover to be held open in two different positions and to be easily removed from the base. Each of the above features is separately novel, and the novel combination of all the features results in a microwave griller that should be a welcome addition to an upscale kitchen
The present invention provides an appliance for converting microwave energy to heat and applying the heat to a grillable food or other grillable substance, the appliance comprising: a first grill element including a microwave absorbent material and a heat conducting element, the heat conducting element having a first surface in contact with the microwave absorbent material and a second surface adapted to contact said grillable food or other grillable substance, a microwave transparent base adapted to support the grill element with the absorbent material spaced from the base, the base and heat conducting element enclosing the absorbent element, and a liquid-tight seal between the grill element and the base. Preferably, the seal comprises an epoxy glue. Preferably, the epoxy is a flexible epoxy. Preferably, the epoxy is a silicon-based epoxy. Preferably, the seal further comprises a first lip on the heat conducting element and a second lip on the base, the first and second lips overlapping, and wherein the epoxy glue is located between the lips.
Preferably, the first lip is spaced from the microwave absorbent material. Preferably, the heat conducting element includes a first trough between the first lip and the second surface, the first trough having sufficient capacity to effectively prevent grease and liquids generated in the grill process from overflowing the grill unit. Preferably, the first trough has a capacity of between 20 milliliters (mls) and 50 mls. Preferably, the trough forms a rim about the first surface, and wherein the microwave absorbent material lies in the recess formed by the rim. Preferably, the appliance further comprises: a second grill element including a second microwave absorbent material and a second heat conducting element, the second heat conducting element having a third surface in contact with the microwave absorbent material and a fourth surface adapted to contact the grillable food or other grillable substance, a microwave transparent cover adapted to support the grill element, the cover and the second heat conducting element enclosing the second absorbent element, and a liquid-tight seal between the second grill element and the cover. Preferably, the second seal comprises a third lip on the second heat conducting element and a fourth lip on the cover, the third and fourth lips overlapping, and wherein epoxy glue is located between the third and fourth lips. Preferably, the third lip is spaced from the second microwave absorbent material. Preferably, the second heat conducting element includes a second trough between the third lip and the third surface, the second trough having sufficient capacity to effectively prevent grease and liquids generated in the grill process from overflowing the grill unit. Preferably, the second trough has a capacity of between 10 mls and 30 mls.
In another aspect, the invention provides an appliance for converting microwave energy to heat and applying the heat to a grillable food or other grillable substance, the appliance comprising: a first grill element including a first microwave absorbent material and a first heat conducting element, the first heat conducting element having a first surface in contact with the microwave absorbent material and a second surface adapted to contact the grillable food or other grillable substance, a microwave transparent base adapted to support the grill element, the base and first heat conducting element enclosing the first absorbent element, a second grill element including a second microwave absorbent material and a second heat conducting element, the second heat conducting element having a third surface in contact with the microwave absorbent material and a fourth surface adapted to contact the grillable food or other grillable substance, a microwave transparent cover adapted to support the grill element, the cover and the second heat conducting element enclosing the second absorbent element; and a hinge assembly adapted to: permit movement of the fourth surface relative to the second surface with the fourth and second surfaces remaining substantially parallel; permit rotational movement of the cover about said hinge; and to support the cover in first stop position located at a point corresponding to a rotation about the hinge of between 90 degrees and 180 degrees. Preferably, the hinge assembly is further adapted to permit the cover to lie flat on a flat surface at a second stop position located at a position corresponding substantially to a rotation about the hinge of 180 degrees.
The microwave grill according to the invention not only provides, for the first time, a microwave griller that achieves the degree of reliability and ease of use expected for kitchen appliances today, but also provides a simplicity of design that permits it to be constructed in modem, efficient assembly plants. Numerous other features, objects and advantages of the invention will become apparent from the following description when read in conjunction with the accompanying drawings.